1. Preheat your oven to 350°F or 180°C.

2. Melt the butter in a large saucepan over medium heat then add the sliced onion. Cook until it softens, which should take about 5 minutes.

3. Next, add the sliced red bell pepper and continue cooking for another 2 to 3 minutes until tender.

4. Add the edamame, fish stock, white wine, and half a cup of fish broth to the saucepan. Bring the mixture to a simmer and cook for 5 minutes, or until the edamame is tender.

5. Heat a tablespoon of butter in a separate pan over medium heat. Add the cod and salmon fillets and cook until opaque and flaky, flipping the fish halfway through the cooking time of about 3 to 4 minutes per side.

6. Return to the saucepan and add the crème fraiche (or sour cream), paprika, salt, black pepper, and cayenne pepper if desired. Stir well to combine all the ingredients.

7. Now add the cooked cod and salmon to the saucepan, along with one and a half cups of fish broth and some water. Bring the mixture to a simmer and cook for 5 to 7 minutes, or until the sauce has thickened slightly.

8. Add fresh spinach leaves and stir them into the sauce. Continue cooking until they wilt, then add cooked shrimp to the saucepan and cook for 2 minutes more, until pink and cooked through.

9. Serve the seafood medley hot. You can garnish it with chopped fresh parsley or dill if desired.